According to the petition, the stars say they can no longer "dine with a clear conscience" at the establishment.

"As customers and fans of Nobu we strongly feel that bluefin tuna must be completely removed from your menu due to its perilous position as an extremely endangered animal," the statement reads.

"Nobu is a restaurant we all love, a world leader in sushi with a fantastic reputation and enormous influence. If Nobu took a definitive stand on this issue it could make a critical difference."

Last month, the owners of Nobu took a small step toward acquiescing, adding a disclaimer to the bottom of its menu noting that the fish is "environmentally threatened" and advising concerned customers to "please ask your server for an alternative."

"The possibility that the magnificent bluefin tuna, one of the fastest creatures on the planet, could be extinct in as little as four years is a tragedy," the celebs' petition reads. "Continuing to serve bluefin leaves Nobu vulnerable to public criticism and lagging behind Moshi Moshi, Gordon Ramsay, Jamie Oliver, Itsu and numerous others."

A spokesman for the restaurant has since said it takes the issue "very seriously." The stars have demanded a more thorough response from owner and chef Nobu Matsuhisa by the end of today (World Ocean's Day, as it happens).

The petition was released in conjunction with the new documentary End of the Line, which is intended to do for the plight of overfishing the world's waters what An Inconvenient Truth did for global warming.

However, not everyone was so eager to add their names to the petition. One star whose name doesn't appear (other thanJeremy Piven, that is): Robert De Niro, a co-owner in the restaurant.